我在模型php codeigniter中的总和查询有什么问题？

Question

here's my model code :

function total($id)
    {
        $this->db->select_sum('score');
        $q = $this->db->get('my_table');
        $this->db->where('id',$id);
        $this->db->group_by('id');
        return $q->row()->score;  

    }  

why the output still sum all of row not the specific row with id?

Answer 1

$this->db->get() actually runs the query. You need to call that last.

function total($id)
    {
        $this->db->select_sum('score');
        $this->db->where('id',$id);
        $this->db->group_by('id');

        $q = $this->db->get('my_table');
        return $q->row()->score;  

    }